The invention relates to the anode superstructure of a fused salt electrolytic cell for producing aluminum, with anode conductor sections which are spaced apart and feed electric current to anode rods supporting the anodes, and also relates to a pot room fitted with the same.
In order to produce aluminum by the fused salt electrolysis of aluminum oxide, the latter is dissolved in a fluoride melt comprised for the main part of the cryolite. The cathodically precipitated aluminum collects under the fluoride melt on the carbon floor of the cell, the surface of the liquid aluminum itself forming the cathode. Dipping into the melt from above are anodes which is conventional processes are made of amorphous carbon. Oxygen is formed at the carbon anode as a result of the electrolytic decomposition of the aluminum oxide. This oxygen combines with the carbon of the anodes to form CO.sub.2 and CO. The electrolytic process takes place in a temperature range of about 940.degree.-970.degree. C.
In the course of the electrolytic process the electrolyte becomes depleted in aluminum oxide. At a lower concentration of 1 to 2 wt.% aluminum oxide in the electrolyte the anode effect occurs whereby the voltage rises from e.g. 4-5 V to 30 V and more. Then at the latest the crust of solid electrolyte must be broken open and the aluminum oxide concentration raised by adding fresh alumina.
The efficiency and thereby the area covered by modern aluminum reduction cells is always being increased. The applied currents exceed 200 kA and can be as much as 300 kA. The anodic part of the cell is becoming more complicated, as is to be expected with more efficient, larger cells with fully automatic control. In recent times therefore the supply of alumina to the cell has been increasingly made using at least two point feeder units each of which features a silo and a measured feed and crust breaker facility. Another trend is no longer to raise or lower all the anodes together but to do this individually.
Working on the anode superstructure above the hooding to carry out inspection and repair these presents health and safety problems.
It is therefore an object of the invention to develop a means of easy access to all essential positions on the anode superstructure, which enables safe and hygienically acceptable working conditions for carrying out the necessary inspection and small repair work on modern molten salt reduction cells used to produce aluminum.